Not sure if this has been an issue for anyone or if it has been covered but thought id share my recent experience with my very noisy ctl midi.
it had become more and more noisy lately and starting to sound like a jumbo jet, suction seemed ok but was getting on my nerves and thought it could explode any moment! given the price of a new motor i looked around at cheaper non oem parts but wasnt sure which one i needed so i opened up the midi to get the part number and visualization of the motor i have but quickly noticed the problem; i had quite a lot of build up of drywall dust stuck inside the impeller which i logically assumed was unbalancing it, i had a similar problem with my tumble dryer having fluff stuck insides its fan making it really noisy.
so needless to say i cleaned it all out, it was stuck in there quite well and i had to kind of gently poke it out with a piece of plastic, i reassembled and is as good as new! not sure if the bearings were damaged or how much longer they will last but if anyone uses their midi for drywall it may be a good idea to clean it out now and then.
